A64Pilot

Which is why as much as is possible you should buy the airplane you want. Don’t buy one thinking I can have this added, new engine and prop etc as it will almost always cost significantly more than the airplane equipped already with a low time engine etc. The converse of that is if you put 50K into Avionics, you won’t get 50K more for it when you sell, or 50K into a new engine etc.

Only failures I’ve seen were in turbines, from excessive over temps literally melting the probe tip, once on a T63-A700, hot start, motor cooked. Of course I’ve seen several where dirty connections, loose grounds etc. caused erroneous readings, but as those were fixed without changing the TIT harness I don’t consider that a harness failure. Turbines usually have several, like 7 probes all in a harness that forms a ring that is mounted so that it measures the temp at the entry of the first stage turbine, that being the hottest place. A Garrett oddly measures the temp of the Exhaust gasses after it’s passed through all the turbines, which I was always taught wasn’t very accurate for a turbine engine, a turbine usually gets the worst heat stress at the first stage turbine so you want to measure temp there, depending on how efficiently the turbine is operating the temp drop to exhaust can be large so you don’t really get a good idea how hot the hottest section is. But Garrets are weird, good motors, just different. ‘The EI guy could tell us, they have sold thousands and I bet failures are pretty quick and are from manufacturing defects more than anything.

I understand turbine prices, and turbine ITT harnesses aren’t single probes either, I’m trying to remember a Garrett may be as it’s an EGT measurement, not an ITT on a Garrett. While PWC may not warranty their hot sections without changing the harness it’s not a life limited item, it’s not required to be changed. No one that I knew sent an airplane to PWC for a hot section inspection, usually done by an IA or Covington Aircraft. I guess Corporate is a different world. None of this has anything to do with the fact that a K type EGT probe, is a K type EGT probe It’s simply an Alumel and Chromel wire connected together that makes a tiny current when heated, that’s it. Bigger wires for higher temp. I’ve not seen one wear out On edit, aging and drift exist, but the changes are minor a few degrees over 1,000’s of hours.

I understand why ITT / EGT is important in a Turbine. I’ve got way more turbine time than recip, and ALL my test pilot time is in turbines. Majority of my mechanic experience is with turbines too. It’s important because most turbines are easily over-temped and over-temping is destructive and very expensive. My point is that Turbine probes don’t deteriorate significantly as they age, if they did then there would be a life limit on them, and there isn’t, because of the importance of not over temping a turbine, on the Million dollar plus GE engines in Apaches and Blackhawks we don’t even calibrate them, and turbines live much longer lives than recips. As far as I can tell the thermocouples for a turbine and a recip are nearly identical, so why do recip ones deteriorate so quickly? I don’t think they do. If an engine is slowly over time increasing EGT, my bet it’s from compression loss from normal wear, not degrading probes.

Ever heard of a “speed sleeve” It’s for a crankshaft that the oil seal had worn a groove in it, a speed sleeve is a very thin very hard sleeve that is slid onto the crankshaft and as it’s much harder metal than the crank it doesn’t wear. https://www.skf.com/us/products/industrial-seals/power-transmission-seals/wear-sleeves/skf-speedi-sleeve If that parts is unavailable I think you could turn it down and put a very thin sleeve on it. Oh and the white dots are “awl” vents, I think it’s to release trapped air in the manufacturing process. Sometimes they are green, maybe for tubeless? https://www.dunlopaircrafttyres.co.uk/technical/red-blobs-and-green-spots/

Without a way to ensure the thing isn’t coming out of the tube on the airplane I won’t pull hard on mine, that’s how I ended up on my back twice, when your pulling hard and it pops out, your going down, your actually down about the time you realize it popped out, and of course you could really hurt yourself that way. So pushing or pulling on the prop is what I do, at the center of course. I wrapped self amalgamating rubber tape on it because it’s grippy, but also soft so it doesn’t last long. Ran into a Sidewinder here for a good price and just bought it, the golf cart works, but to turn the aircraft around etc I’m at max deflection it worried me, figured I couldn’t hurt anything with the Sidewinder, but could with the golf cart. I toyed with the idea of welding in a heavy spring in the tow bar so you couldn’t hurt anything but as my Agricultural contacts are gone I don’t know where to get such a spring, Combines etc are full of the things. In Florida where there is no snow etc to deal with the Sidewinder seems to be pretty much ideal. It’s 22 lbs if anyone was wondering and folds so it fits in the baggage. For the price I wish they had made it from aluminum tubing, but it’s extraordinarily well made with ideal chain tension adjustments etc. Well thought out.

And you get a different mag drop on run-up too, makes you wonder why the different timing. Does it act like one longer spark?

Actually only need two pieces of 3/4” iron pipe and one elbow. four pieces and a T if you want a two handed handle. The 90 degree issue is solved by using a much longer piece that goes in the wheel, make it as long as the tube on the airplane and it won’t slip out. I put one together as a tow bar for my golf cart out of 3/4” pipe and it works fine, for that it took three pieces and two 90 degree elbows. I have a nice pretty chrome one that came with the airplane, the end that goes into the airplane is less than 90, yet it has put me on my back twice before knocking up the pipe one for the golf cart. Both times I was washing the airplane, being wet I think made it slip out easier.

Some engines have dual impulse couplings, my 1946 C-85 does and it even has an odd different timing for each mag. 2 degrees different from memory I had always assumed one was deleted as a cost savings? I too am leery of electronic mags, they should be dead reliable as in never, ever fail, but that doesn’t seem to be the case? Seems I’ve seen quite a few posts about problems.

Are they like these? https://mooneyspace.com/topic/45443-trim-indicator-glass/

I wouldn’t put heat on one unless removed, and if it’s removed I’d replace it. ‘I’ve not seen them on a bravo, I’m assuming flat pieces of plastic?

Sometimes cleaning the connections to the probe can correct errant readings

Why would a turbine be different? Same type of thermocouple, just usually a turbine has several and an average measurement is taken. 30 min temp limit on what I used to fly was 867C which is right at 1600F, so even temps are close.

Even with a calibration it’s temporary, during Certification test flights I had to have everything calibrated within 90 days, even if not installed 90 days was the limit. Then there are single point calibrations and multi point, FAA required multi point cals, which they should. I got stung once with a Scale, we were Certifying the S2R-T660 and discovered one cell read incorrectly, it was within the 90 day cal but was reading incorrectly, so when did it go bad? That started a mess, some demanded we re-start the Cert flights from the beginning and repeat them all, we settled on just repeating the ones at the max fwd and rearward limits. I had the welder weld up a steel box and we put 600 lbs of lead shot in it, then every time before we weighed an aircraft we took the overhead crane and weighed that box with all three cells. On edit, we “Jet-cal” the older aircraft in the Army OH-58, UH-1, OV-1’s etc to calibrate the temp indicating system. But the newer aircraft, AH-64’s, UH-60’s etc we didn’t. I always wondered why not, but we didn’t. Having said that on my MVP-50 I installed on my Maule I had 14 thermocouples, 6, egt, 6 cyl, 1 oil and 1 OAT. If left in a hangar for more than 24 hours they would all read within one degree, which astonished me, maybe these newer ones are dead on balls accurate?

If chrome, unlikely they have corrosion, chrome doesn’t seal well and high oil consumption is normal, chrome is very hard and suffers very little from wear, usually the end of a chrome cylinder is when the chrome begins flaking off, if you do oil analysis that should tell you when that happens. Chrome is mostly gone for several reasons, the new plating on the block is different forms of Nickel plating, which has been used successfully for years in especially the motorcycle industry, but then so was chrome. Nikaseal, Cermichrome, and other variations of Nickel may prove to be very superior to plain steel. One thing it’s additional price is pretty minimal so price isn’t a reason to not go with it. I personally would not replace them with chrome

Be sure to inspect it and put some kind of corrosion preventative on it, and put it in a large zip loc bag with a bag of desiccant. I knew someone who bought a crankshaft from Lycoming for the AD when Lycoming sold them at a discount, AD specified replacement at overhaul so he put it aside, when overhaul came he opened it up to find excessive corrosion, second crankshaft he had to pay full price.

One thing I should throw out here is that an A&P requires significant education or OJT and several tests. To be an aircraft manufacturer whether working at a factory manufacturing Type Certificated aircraft or building say an RV, there are no requirements at all, that’s right zero, none at all. I’d say on average of the 80 or so people actual building the aircraft I had 2 or 3 A&P’s. That was in the entire factory, there were zero A&P’s in Quality Control and I was the only Corporate officer that had one. An A&P is actually a pretty highly skilled person, and rarer than you might suppose

Yeah that’s a good pre-flight, not a pre-buy. I tell everyone so I’ll tell you, A pre-buy is a non defined term, it can mean anything at all and can be performed by anyone at all with no performance criteria. My advice is start a pre-buy and only after everything important seems to check out turn it into an Annual. If I had a dollar for every time I’ve heard the pre-buy didn’t find it, but the first Annual found severe corrosion that likely totals the airplane, replacement wings needed etc. I could buy an Autopilot. If a pre-buy was conducted correctly then nothing of consequence should be found in an Annual, but somehow there are several threads where something was. Compressions etc are insignificant compared to serious corrosion.

That’s exactly the advice given to me by a very experienced Ferry pilot, if you KNOW one is empty then you’re more likely to divert and land etc. but if you have fuel in both sides your more likely to overestimate the amount of fuel remaining. So far as running out of fuel, it’s exactly like it us in a car etc. you’ll lose power, then it usually comes back, engine may stumble etc., but you switch tanks and it comes back, remember the prop will keep windmilling. I’ve not had one just suddenly stop with no warning. Personally I burn 10 gls then switch tanks, If I burn 20 out of a tank then I consider it empty. I have bladders so I hold something like 54 or something, I forget. I don’t even come close to pushing fuel, those days are behind me

A quart every five hours or so is fine. From what I see it does look like you have some corrosion pitting, but with compressions at worst at 76 and without oil fouling plugs I’d advise putting cylinder money into Avgas and enjoy flying. It’s likely over time your oil consumption will improve some. You’ll know when it’s time when you begin oil fouling plugs and she will lose some power. Ideal world you would buy new cylinders, I’d start saving knowing it’s in your future but for now I’d keep flying. It’s real easy to spend so much that there isn’t enough left in the budget to fly.

I have, the light is off and I think it’s red, not sure about the red part but I think it is

Mineral spirits is a very good cleaner, but I use Gunk and a very cheap pressure washer and use it only to rinse, I don’t put any significant pressure on anything. Mineral spirits is often used without a water rinse, that’s it’s advantage, it doesn’t require water. Military we were only allowed to clean the engines with Mineral spirits, we weren’t allowed to use water. Apply the gunk to a dry warm, not hot engine A garden hose would be fine, you don’t want to put any significant water pressure on anything. Don’t get any cleaner in your alternator and I stay away from the Mag (s) too On edit a solvent gun works well with Mineral spirits, just be wary because it’s very flammable, it’s charcoal starter fluid after all.

Take a teaspoon of oil heat it up until it’s as thin as water, add in over 100 MPH of wind and it will cover the entire belly.

How many hours on the engine? Do a compression check primarily listening for where the air is leaking past more than just the numbers. What did the plugs look like? I agree it didn’t all come out of the dip stick, but that’s too easy a fix not to fix. Now this is going to sound strange but I have seen a leaking as in sucking air into dip stick drive oil consumption up, belief was that a vacuum was created and it was sucked out the blow-by tube. I don’t think that will fix your issue, but the leaking dip stick tube is an easy fix, it’s just a gasket. Oh and I’m not one that believes in ring gaps aligning either

I believe that article is for turbo motors, specifically the TIO-540J Not saying there isn’t one, but I’ve never seen a recommended max for NA motors. Piston temp and valve temps are much lower than EGT, I typically cruise around 1400F and peak about 1475F but the typical piston alloy will melt at roughly 1200F. Forced induction can raise temps well beyond what a NA motor can get to, I don’t think my NA motor can get to 1650 under any conditions, so I suspect there is no need to spec a max EGT for a NA motor, because it just can’t hurt itself with EGT.